[Visualpython-users] VP and PyGL thoughts

[Hugh F. <hug...@an...>]

Some thoughts regarding possible implementations of Visual
Python on top of PyGL. (Scene graphs in the next message.)

Implementing Visual Python on top of PyGL wouldn't get rid
of all the C++ code. PyGL wraps the OpenGL API, but that
doesn't cover window creation or keyboard/mouse handling.

The big advantage I can see of using PyGL is that new
graphical primitives could be written in Python and added
at runtime, instead of the current requirement to write
them in C++ and rebuild cvisual. As Jonathan points out,
all the primitives in VP are static geometries so can be
compiled into display lists. The overhead of OpenGL calls
in Python rather than C++ would be minimal and I doubt
anyone would notice.

Jonathan observed we could use GLUT for window, keyboard,
and mouse handling. GLUT is simple, but it might be worth
thinking about wxPython which is a cross platform GUI
toolkit instead.

Or, just leave the window management and event handling
in C++ as done now.

The major disadvantage is that it introduces a dependancy
on another piece of software. One of the things that makes
Visual Python great is that you download it and it Just
Works. (Well, almost always.) Basing VP on PyGL means
having to point users at another download site, or shipping
a copy of PyGL with every copy of VP, or ... I'm sure it
can be done, but is it worth the hassle?

-- 
	Hugh Fisher
	DCS, ANU